I did take some ePub eBooks with me on an SD card that are 100% complaint with how fonts are to be embedded. And they work with the desktop ADE. The fonts did not display with either the Kobo wifi or Kobo original. It should not be a matter of if the fonts are done this way they work and if they are done that way, they don't. The fonts were done in a correct way and they did not display.
So since the issue of embedded fonts has been brought up a number of times, why haven't they been addressed at all?